Railway signaling system



Feb. 25, 1930. H OBER 1,748,788

RAILWAY S IGNALING SYSTEM Filed June 22, 1928 INVENTO Hermon Ober hATTORNEY 1 Patented Feb. 25, 1930 UNITED6 STATES PATENT OFFICE HERMON I.OBER, OF ROCHESTER, NEW YORK, ASSIGNOR TO GENERAL RAILWAY SIGNALCOMPANY, OF ROCHESTER, NEW YORK RAILWAY SIGNALING SYSTEM Applicationfiled June 22,

This invention relates in general to a railway signal system, and hasmore particular reference to a signal for controlling trains at stationplatforms.

In the operation of railway trains, and in subway operation inparticular, it is desirable to limit the time a train should occupy thetrack adjacent the loading and unloading platforms, inorder to expeditetraffic and 10 avoid confusion at platform locations.

With the above object in mind, it is proposed in accordance with thisinvention to provide automatic means for giving a signal when a traincan be expected to leave a loadl5 ing platform, with means forinitiating the signal only after the train has been along side theloading platform for a predetermined time, together with automatic meansfor cutting out the signal- More specifically, this invention providesmeans whereby, after a train has been brought along side a loadingplatform, a time element relay is energized, which relay, after apredetermined time interval, as for example 25 seconds, is effective toenergize a signal, such as an electric bell. Upon energization of thesignal, time element, such as a thermally controlled device is caused tofunction, and is effective after a predetermined time interval, as forexample 5 seconds, to de-energize and thereby silence the bell. In thismanner a second time interval is allotted to a train at a platform, witha signal given during the last five seconds of the allotted time, towarn the traveling public, and advise the train crew that on silencingof the signal, the train should be operated to clear the section oftrack adjacent the loading platform.

Further objects, purposes, and characteristic features of the presentinvention will appear as the description progresses, reference being hadto the accompanying drawing, given wholly by way of example and not inany manner in a limiting sense, where- The single figure of drawingrepresents,

in a wholly diagrammatic manner, one form which applicants invention canassume.

Referring now to the drawing, there is shown a stretch of track,including track rails 1928. Serial No. 287,394.

1, divided by means of insulating joints 2, into separate insulatedtrack sections or blocks A,

B, etc. Each track section or block includes a source of energy such asa track transformer connected to an A. C. supply, or a battery 3connected across the rails at one end of the block, and a track relay Tconnected across the track rails at the other end of the block. At theentrance end of block B, traflic being assumed to be in the direction ofthe arrow, is positioned a trafiic signal shown as a light signal butwhich can, of course, be of any other desired type such as a semaphoreor the like. This signal 4 is controlled in an automatic manner, inaccordance with tralfic, in

any desired or known way, such for example as shown in the PeabodyPatent 1,627,453 granted May 3, 1927, it being deemed unnecessary forthe purpose of the present invention, to show, or further describe, thesig- 7 nal control.

Positioned along side the tracks of block B is a loading and unloadingplatform 5, such for example as is very generally employed in connectionwith subway lines.

Included in this invention is a main control relay 6, a signal S, asignal cut out relay 7, and a thermal relay R.

The main control relay 6 is preferably an alternating current relay,although of course so a direct current relay could be employed, andincludes a time element, preferably of the mechanical type, whereby therelay moves its contact fingers 9, 10 and 11 to attracted position onlyafter the lapse of a predetermined time after it is energized, in thepresent case approximately 25 seconds. Relay 6 is quick releasing so asto release its contact fingers immediately on de-energization.

The cut-out relay 7 is shown as an alternating current relay andreasonably quick to pick up and release, and is furnished with twocontact fingers 12 and 13.

The signal S is shown as an electric bell of any lmownor desired type,which gives an audible signal on energization and is silenced onde-energization. This signal can however just as well be any other typeof audible signal such as a horn or the like or could be a visual orother kind of signal if desired.

The thermal relay R includes an insulating base 14, having relativelystiff conducting arms 15 and 16 connected thereto and normallypositioned to have their contacts 17 spaced apart, there being a heatingcoil 18 carried on the arm 16 and connected electrically to the arm 16at its two ends. Connected to the heating coil 18 at its central point,is a conducor 19, the coil 18 functioning when energized to heat the arm16 and cause it to move to bring the contacts 17 together. The heatingcoil 18, can, of course be end fed and connected at but one end to thearm 16, if desired, or any other desired connection can be employed.

The arrangement shown also includes a resistance 8 which is considerablyless than the resistance of the relay 7, (in one satisfactoryarrangement, the ratio being 2 to 3), for purposes which will be clearas the description progresses. If alternating rather than direct currentbe employed, this member 8 will be an impedance bearing the samerelation to the impedance of the relay 7 as just set forth.

In order to simplify the wiring diagram, the letters B and C areemployed to represent the opposite terminals of a source or sources ofelectrical energy of either direct or alternating current.

The invention will perhaps he most readily understood by describing itsoperation through one complete cycle.

Assume a train moving on the track rails 1 in the direction of thearrow. On occupancy of the approach block A, track relay T becomesde-energized and releases its contact finger 20. As the train progressesand occupies the platform block B, track relay T becomes de-energizedand releases its contact finger 21. Thus far this progress of the trainhas had no effect upon the platform signal apparatus, and it is onlyafter the rear end of the train has passed wholly out of the approachblock A, so as to re-energize track relay T, that a pick up circuit iscompleted for the main control relay 6 which circuit can be traced asfollowsz-from one terminal B of a source of energy, contact finger 21and back point of relay T, contact finger 20 and front point of relayT", the winding of relay 6, to the opposite terminal C of a source ofenergy.

As described above this relay 6 is furnished with a time element whichcauses the relay fingers, 9, 10 and 11 to be moved to attractedposition, only after 25 seconds after energization. Relay 6 now remainsenergized regardless of whether or not approach block A be occupied,through a stick circuit which includes in series, contact finger 9 andfront point of relay 6, and contact finger 21 and back point of relay T,the remaining portions of this stick circuit being obvious from thedrawing.

As soon (25 seconds after relay 6 is energized) as contact finger 10 ofrelay 6 is moved to attracted position, an energizing circuit for thebell signal S is completed which includes in series contact finger 10and front 3011113 of relay 6, and contact finger 13 and back point ofthe cut-out relay 7.

Movement of contact finger 11 of relay 6 to attracted position completesan energizing circuit for the coil 18 on thermal relay R which circuitincludes, contact finger 11 and front point of relay 6, wires 22 and 19,coil 18, arm 16, wire 24, contact finger 12 and back point of relay 7and the resistance unit 8. It will be noted that this coil 18 of the,thermal relay R is energized simultaneously with the energization ofthe signal S.

As described above, energization of the heating coil 18 causes thecontacts 17 to come into contact approximately 5 seconds after suchenergization, which results in completing a pick up circuit for the cutout relay 7 which circuit includes contact finger 11 and front point ofrelay 6, wires 22 and 19, coil- 18, contacts 17 in closed position. arm15, wire 23, and the winding of relay 7. Upon energization, relay 7moves its contact fingers 12 and 13 to attracted positions.

Raising of contact finger 13 of cut out relay 7 breaks the energizingcircuit for the signal S which results in silencing the signal.

The movement of contact finger 12 of relay 7 to attracted positionbreaks the energizing circnit for heating coil 18 of thermal relay R,which passes through the resistance unit 8, as traced above, and at thesame time completes a stick circuit for relay 7 which includes thewinding of relay 7, contact finger 12 and front point of relay 7, wire24, arm 16, winding 18 of thermal relay R, wires 19 and 22, and contactfinger 11 and front point of control relay 6. It will be seen that theheating coil 18 of the thermal relay R is still energized but that it isnow in series with the winding of relay7 and that, as described above,the resistance of the winding of relay 7 is considerably greater thanthat of the resistance unit 8, whereby insufficient current flowsthrough the heating coil 18 to maintain the contacts 17 closed so thatthe arm 16 immediately begins to cool off.

On silencing of the signal S after it has sounded for 5 seconds asdescribed above, the, train crew is advised that the train should start,and the travelling public has been warned, and upon the rear end of thetrain passing out of the platform block B, track relay T will pick upand thereby break the stick circuit for control relay 6, at the contactfinger 21 of track relay T. Control relay 6 lmmediately releases itscontact fingers 9, 10 and 11, the contact finger 9 breaking the stickcircuit for relay 6 at a second point, the contact finger 10 breakingthe energizing circuit for the signal S at a second point, and thecontact finger 11 breaking the stick circuit for relay 7 and alsobreaking the pick up circuit for this relay 7, which would otherwise beclosed if contacts 17 of thermal relay R had not yet opened. Thus allthe various parts are restored to normal position as shown in thedrawing.

It should be noted that signal 4, if observed, prevents entrance of afollowing train into block B until after this block has been cleared bythe forward train so that it is insured that track relay T shall releaseupon the forward train clearing block B to thereby restore the variousparts of the system to normal.

By having the stick circuit for relay 6 independent of the track relayT, occupancy of the advance block A, while a train is in block B, cannotinterfere with the operation of the system.

As brought out above, byhaving the resistance 8 considerably less thanthat of the winding of relay 7 the heating coil 18 of thermal relay Rbegins to cool off as soon as relay? has picked up which is, of course,a desirable feature since it is necessary that the contacts 17 of relayR be open by the time a following train has moved along side theplatform 5 sufficiently to have its rear end clear the approach block A.

The above rather specific description of one form of this invention hasbeen given solely by way of illustration, and is not intended,

a in any manner whatsoever, in a limiting sense. Obviously, theinvention can assume many different physical forms, and is susceptibleof various modifications, and all such forms and modifications areintended to be covered by the present invention, as come within thescope of the appended claims.

Having described my invention, I now claim 1. In asignal system, asection of track divided into insulated blocks, a signal, control meanseffective on occupancy of one of said blocks, only if another of theblocks be unoccupied, to initiate said signal, and a signal cut outmeans initiated by said control means and effective a predeterminedperiod of time after initiation to render said signal inactive.

2. In a signal system, a section of track divided .into insulatedapproach and platform blocks, a signal, control means effective onoccupancy of said platform block if said approach block be unoccupied toinitiate said signal, a signal cut out means initiated by said controlmeans and eflective a predetermined period of time after initiation toren der said signal inactive.

3. In a signal system, in combination, a section of track divided intoinsulated approach and platform blocks, a normally inactive signal, acontrol relay operable a predetermined time after energization to makesaid signal active, and means energizing said control relay on occupancyof said platform block only if said approach block be unoccupied.

4c. In a signal system, in combination, a normally inactive signal, acontrol relay open able a predetermined time after energization to makesaid signal active, and a signal cutout means initiated substantially atthe time said signal is made active and effective a predetermined timeafter initiation to make said signal inactive.

5. In a signal system, in combination, a normally inactive signal, acontrol relay operable a predetermined time after energization to makesaid signal active, a thermal cut out means for said signal energized bysaid control relay at the time said signal is made active, said out outmeans operating a predetermined time after energization to make saidsignal inactive. I

6. In a signal system, in combination, a platform, a section of trackadjacent said platform, a signal, control means effective only apredetermined time after occupancy of said section of track to initiatesaid signal, and a signal cut out relay initiated simultaneously withsaid signal and effective a predetermined time after initiation to cutout said signal.

7. In a signal system, an insulated section of track, a signal, acontrol relay energized on occupancy of said section and effective onlya predetermined time after energization to initiate said signal, asignal cut out relay, a thermal relay energized by said control relaysimultaneously with the initiation of said signal, and a circuitcont-rolled by said thermal relay a predetermined time afterenergization of the thermal relay to cause said out out relay to assumeits signal cut out position.

8. In combination, in a signal system, a section of track divided intoinsulated approach and control blocks, a track relay for each of saidblocks, a signal, a control relay for energizing said signal having apick up circuit including in series a front point and a back point,respectively, of said track relays and a stick circuit including a backpoint of said control block track relay but not of said approach blocktrack relay, and means controlled by said control relay forde-energizing said signal.

9. In combination, in a signal system, a section of track divided intoinsulated approach and control blocks, a track relay for each of saidblocks, a signal, a control relay for energizing said signal having apick up circuit including in series front and back points, respectively,of said track relays and a stick circuit including a back point of saidcontrol block track relay but not of said approach block track relay, athermal relay, and

a cut out relay for de-energizing said signal having a pick up and astick circuit each including a front pointof said control relay, saidpick up circuit for said cut out relay also including contacts of saidthermal relay. 10. In combination, in a signal system, a section oftrack divided into insulated approach and control blocks, a track relayfor each of said blocks, a signal, a control relay for energizing saidsignal having a pick up circuit including in series a contact point ofeach of said track relays and a stick circuit including a contact pointof but one of said track relays, a thermal relay, and a cut out relayfor de-energizing said signal having a pick up and a stick circuit eachincluding a front point of said control relay, the pick up circuit forsaid out out relay also including contacts of the thermal relay, saidthermal relay including a heating coil having an energizing circuitincluding in series a front point of saidcontrol relay and a back pointof said out out relay.

11. In combination, in a signal system, a section of track divided intoinsulated approach and control blocks, a track relay for each of saidblocks, a signal, a control relay for energizing said signal having apick up circuit including in series front and back points, respectively,of each of said track relays and a stick circuit including a back pointof said control block track relay but not of said approach block trackrelay, a thermal relay having normally open contacts, a cut out relayfor de-energizing said signal and having a pick up, and a stick circuit,each circuit including a front point of said control relay, said pick upcircuit for said out out relay including said contacts of said thermalrelay, and a heating coil in said thermal relay which, when energized,closes said normally open contacts and having an energizing circuitincluding in series a front oint of said control relay and a back point0 said cut out relay.

12. In a signal system, in combination, a platform, a section of traclnadjacent said platform, a signal, control means effective only apredetermined time after occupancy of said section of track to initiatesaid signal, and a signal cut out relay effective a predetermined timeafter initiation to cut out said signal.

In testimony whereof I afiix my signature. HERMON P. OBER.

